%0 Journal Article %A A. D. Aleksandrov %T A theorem on triangles in a metric space and some of its applications %J Informatics and Automation %D 1951 %P 5-23 %V 38 %I mathdoc %U http://geodesic.mathdoc.fr/item/TRSPY_1951_38_a1/ %G ru %F TRSPY_1951_38_a1